This invention relates to a sheet conveying device provided with means for temporarily interrupting the movement of the leading end portion of a sheet transported from one device to another device.
When a sheet is moved in a first device at a predetermined rate and is transferred to a second device which moves it at a rate higher than the rate of movement of the sheet in the first device, there occurs the problem that the sheet will be pulled between the two devices due to the difference in the rates of movement, if the sheet is delivered to the second device before it is completely discharged from the first device. For example, in a facsimile system an original copy is transmitted by a transmitter and received by a receiver thereof, and a facsimile record of the original copy is printed as an electrostatic latent image on an electrostatic recording sheet at the receiver and developed into a visible image so as to produce a duplicate of the original copy. In such a case, if the recording sheet moves intermittently or at a lower rate in the recording device of the receiver and is transported at that rate to the developing device thereof where it is moved at a higher rate, irregularities will occur in the developed image. This is not desirable.
Proposals have been made to obviate the aforementioned disadvantage by causing the recording sheet to buckle up to a predetermined degree in such a manner that the trailing end of the sheet is released from the recording device before the sheet is tensioned by delaying the initiation of the movement of the sheet in the developing device, so that the leading end of the sheet released from the recording device will not be moved continuously into the developing device. In this system, the leading end of a sheet abuts against a pair of feed rollers on the developing device side whose rotation is temporarily interrupted and the sheet is continuously delivered from the recording device to cause the sheet to buckle up. However, the leading end of the sheet tends to be released from abutting engagement with the feed rollers due to the resilience of the material of the sheet before the size of the loop formed by the sheet reaches a satisfactory predetermined level.